Collaborative Research: A Quantitative Framework for the Flow of Metals in Nearby Galaxies

Chemical elements, such as oxygen and nitrogen, are forged in the interior of stars. When stars end their lives as supernova explosions, many of these elements are expelled and mix into the local environment within a galaxy. These expelled elements are the seeds for future generations of stars and planets. If there are enough supernova explosions, or if the galaxy is small, some of the elements will leave the galaxy entirely and end up in intergalactic space. Therefore, measuring the types of elements in galaxies, and finding where the elements are located, give important clues about the history of galaxies in the Universe. These investigators will perform optical and radio wavelength observations of 36 nearby galaxies to study how galaxies produce, distribute, and expel elements. Their research results will help us understand how galaxies change over time and will be used as input to galaxy formation models. Fundamentally, the observed gas-phase metallicities in nearby galaxies should correspond to the production and release of stellar nucleosynthesis products and, thus, provide a robust trace of galaxy formation and life cycle. Global scaling relations, such as the mass-metallicity relation, show gas-phase metallicities increase steeply with galaxy mass. The investigators seek to build an over-arching, quantitative framework of the production, transport, distribution, and retention of metals in low-mass galaxies. Specifically, they will determine the full chemical enrichment histories of a statistical sample of low-mass galaxies in the nearby universe from a comprehensive set of spectroscopic and imaging data. The investigators, both women astronomers, will work to develop a diverse, globally competitive STEM workforce by working with undergraduate and graduate students on this research project. Additionally, their research highlights will be broadcasted on the public "StarDate" Radio program to an audience of 750,000. The co-investigator will continue to lead nationwide efforts to reduce interference at radio wavelengths. The efforts to reduce radio interference are critical for enabling radio astronomy research. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.